The present invention relates to a large scale information processing system, and more particularly to an information processing system well is suited for constructing a high performance information processing system by dividing a system into plural sub-systems and causing them to cooperate with each other.
A large scale information processing system hitherto proposed includes, as disclosed in JPA-56-111,353 and JPA-56-40,344, functional code communication as a communication system composed of plural equivalent sub-systems called `autonomous basic units`, and sub-system failure detection as a method for detecting failure in the adjacent autonomous basic units by providing a detour in a double loop network, etc. These systems do not consider the functions of the sub-systems or any interference generated among the sub-systems. However, in actually effecting a large scale system of information processing or control, some interference will occur among the sub-systems so that the performance of the entire system does not improve even when the performance of the sub-systems themselves improves.
Moreover, that the autonomous basic units only play their own role (i.e., perform their own function), but do not consider the optimum over the entire system should be noted. The optimum over the entire system can be realized by a supervising or unifying control system for supervising the sub-systems in `hierarchical control`. However, the idea of the supervising control system, has drawbacks. In particular its malfunction directly leads to failure in the entire system, and it must process a vast amount of information for the sub-systems.
In short, the above prior art control systems do not consider the interference among sub-systems nor do they consider the optimum location of the supervising function. This obstacle prevents improvements to the performance and reliability of the system.